The best thing to do, is to have s_x every other day if you are really trying. But sperm can live only about 5 days so if you have more than 5 days before ovulation is it in vain. If you don't want to have s_x that often, you should wait a week after your period ends, and then try for about a week. Are you usually regular (28 day cycle?) Does you period usually come every 23/24 days or so and last for about 4/5 days?

then, about 7 days after your periods ends you should have s_x every other day...man on top, lift legs up and hope for the best. But make sure you are living a healthy lifestyle too - cut out caffeine, smoking, and start exercising and taking prenatal vitamins. I got pregnant quickly in part (i believe) because I was so healthy - jogging, etc.